Fifth Grade Math Vocabulary

DiameterThe distance across a circle through the

center Any chord of a circle that passes

through the center

Examples

Distributive PropertyA number multiplying a sum in parentheses

multiplies each number and then adds the products

It gives the same result as adding first and then multiplying

A property which multiplies a single term with two or more terms inside a set of parentheses

Examples 3 x (4 + 2) = (3 x 4) + (3 x 2)

3(7+4)=(3)(7)+(3)(4)

10*(2+18)=(10*2)+(10*18)

EdgesA line segment where 2 faces of a

3-dimensional figure meet

Examples

             

edge

edges

Equation (Modeling)A mathematical sentence that shows

that two quantities are equalTo solve an equation,

find a value for the variable that makes the sentence true

Examples

XX=2

X = 4x + 4 = 5 x = 1

Expanded FormWriting a number as the sum

of the values of its digits

A way to write numbers by showing the value of each digit

Examples

935 = 900 + 30 + 5

1,579 = 1,000 + 500 + 70 + 9

200 + 70 + 3

=

Expanded form

FacesA flat side of a 3-dimensional figure

Examples

facesface

Improper FractionA fraction whose numerator is

greater than or equal to its denominator

Examples

Improper fraction

5

4

Intersecting Lines Lines that meet or cross at one common

point

Examples

P

Lines EF and GH intersect at point P

The two lines intersect at point (-2,1)

Inverse Operations Operations that undo each other

Examples Addition and subtraction are

inverse operations (undo adding 3 by subtracting 3)

Multiplication and division are inverse operations

(undo multiplying by 2 by dividing by 2)

To solve an equation use inverse operations:x + 3 = 5

x + 3 – 3 = 5 – 3x = 2

MeanOne of the measures of central tendency

It is found by adding the numbers in a data set and then dividing by the number of data points

Example

Given six test scores: 85,87,78,88,88 and 96The mean or average is 87 :

(85+87+78+88+88+96)

6

Metric Units: meter, liter, gramUnits developed in Europe and used in most of the

world

Examples   Quantity          Unit Equivalent        Symbol

      length         meter 3.28 feet           m

      mass         gram  33.8 fl ounces           g

     volume          liter .035 ounces            l

2 liter bottles

Millions

Examples

One million pennies

One million seconds = 277.76 hours

1,000,000

60 60

9, 8 7 6, 5 4 3 Nine million, eight hundred seventy six thousand, five hundred forty three.

610 1,000,000The unit between thousands and billions One million is

Mixed NumbersA number that combines both a whole number and a fraction

4 91

5 5 5

36

5

36

19 1 13 3

6 6 6

Parallel LinesLines that never cross

and are always the same distance apart

They have the same slope

Examples

Perpendicular Lines

Lines which intersect to form a right (90 degree) angle

Examples

PlaneA flat surface extending in all directions

A two-dimensional figure

Examples

Coordinate Plane

Polygon: regular/irregular A closed plane figure for which all sides are

straight line segments

Regular polygons have congruent sides and angles

Irregular polygons

triangle square

pentagonhexagon

heptagon

octagon

nonagon

decagon

Proper Fraction A fraction whose numerator is less than its denominator

Examples

2

1

4

1

Quadrilateral A polygon with four sides and four angles

Examples

Radius A line segment that connects the center of

the circle to a point on the circle

Examples

Ray

A part of a line starting at a particular point, its endpoint, that extends infinitely in one direction

Examples

An angle is made up of 2 rays

Standard Form

A way to write numbers by using the digits 0-9, with each digit having a place value

28 64Exponential form Standard form

= x + x + x

Standard form Expanded Form

19 10339

ThousandthsThe place value that represents

one thousandth of a whole It is one tenth of a hundredth and

one hundredth of a tenth

Examples

1000

1

One Thousandth

Types of triangles (isosceles,equilateral,scalene)

A scalene triangle has no congruent sidesAn isosceles triangle has two congruent sides

An equilateral triangle has all three sides congruent

Examples

Scalene

Isosceles

Equilateral

A right triangle has one right angleAn acute triangle has three acute anglesAn obtuse triangle has one obtuse angle

Examples

Types of triangles (right, acute, obtuse)

Right triangle

Acute triangle

Obtuse triangle

Variable A quantity that can change or that may

take on different values

Examples

4x y x y

0 4

1 3

2 22,000,000

Vertex (or vertices)A corner point of a geometric figure

A point where two sides of a polygon intersectExamples

Vertices

x-axis, y-axis The x-axis is the horizontal number line,

the y-axis is the vertical number line, They form a plane used for graphing points and

linesExamples

X-axis

Y-axis

x-axis

y-axis